This invention relates to a semiconductor memory device and, in particular, to a phase change memory device and to a forming method thereof.
A phase change memory device is disclosed in, for example, US 2005/0185444 A1, U.S. Pat. No. 6,740,921 B2 or U.S. Pat. No. 6,815,705 B2, these documents being incorporated herein by reference in their entireties.
There is a need for a phase change memory device that can effectively supply heat with its phase change portion and can be fabricated easily.